This invention relates generally to stethoscopes and, more particularly, to stethoscopes with detachable diaphragm and bell components which adapt the stethoscope for use on infants, or adults, and in locations of smaller skin areas.
The chest piece of most stethoscopes are the dual head type which consist of a diaphragm on one side and a bell on the other. The diaphragm is suitable for detecting low frequency range sounds associated with diastolic and third heart sounds; the bell is suitable for detecting higher frequency range sounds, such as those which signify murmurs. The chest piece also has a revolvable valve stem which the user rotates to open the desired sound passage. FIGS. 2 and 3 show a typical dual head stethoscope. Typically, for the best detection of sounds, it is desirable to acoustically seal the rim of the diaphragm or bell with the skin of the patient's body above the site to be auscultated. Thus, a diaphragm suitable for use with an adult, is too large to be used on an infant's chest, and conversely, a diaphragm suitable for use with an infant is too small to be used on an adult. As another example, the region between ribs, is more narrow than the chest. The adult sized bell is thus too large to be used on such a location. Since the diaphragm and bell are not removable, various attempts have been made to adapt the dual head stethoscope for multiple uses, i.e. for use with infants as well as adults. For example, U.S. Pat. No. 4,502,562 issued to Carl T. Nelson discloses and claims a stethoscope head with an insert which decreases the surface area of the bell, making it suitable for use with infants.
Another example of the adaptable stethoscope is commonly known as the "Sprague." The Sprague stethoscope is a stethoscope configuration which includes a chest piece including a drum and a stem, and removable diaphragm structures and bell components which attach to the drum. The diaphragm structure includes a disc, attachable to the drum; a ring, attachable to the disc; and a thin diaphragm attachable to the ring. The diaphragm structures and bell components are typically screwed on to the drum. The diaphragm structures and bell components are in various sizes so that the stethoscope may be adapted for use on infants or adults, or on areas where less skin area is available, such as between the ribs. The Sprague stethoscope is further equipped with a dual tube sound passage, which increases the area of the sound passage, thereby increasing the overall sound conductivity. The stem of the chest piece must include an adapter so that both tubes may be connected. FIGS. 4, 5, and 6 illustrate an embodiment of the Sprague stethoscope, including the elements of the diaphragm structure.
A desirable attribute of these stethoscopes is that they increase the usefulness of the particular stethoscope. The stethoscope head disclosed in the Nelson patent presents an insert for the bell portion of a typical dual head chest piece. However, the diaphragm is not adapted, and thus a second stethoscope is still necessary if the user wishes to use a diaphragm sided stethoscope on an infant. The Sprague stethoscope offers the user more useful adaptations of the dual head stethoscope, but because of the dual tubing and additional stem adapter, the stethoscope is heavier than the conventional stethoscope, and more costly to make.
Therefore, there is a need for a lightweight multiple use stethoscope that offers the usefulness of the Sprague stethoscope, but is not as cumbersome, or costly. The subject invention satisfies this need.